As most of the United States prepares to set its clocks an hour earlier overnight on Saturday, it’s time again for frequently asked questions like "Is it better to wake up in the dark, or to go home in the dark?" and "Why are we doing this, again?" Daylight Saving Time ends at 2 a.m. Sunday, November 3, as outlined in 15 U.S.C. § 260a. DST will resume with a "spring forward" on the second Sunday of March.
In 2020, the Congressional Research Service issued a helpful report on Daylight Saving Time. The CRS report details the history of DST in the U.S. and congressional action related to it. DST was first adopted in the United States during World War I, with the Standard Time Act of 1918 (also called the Calder Act). This act created standardized time zones for the United States and set a DST, which was already in place in parts of Europe to help conserve fuel during the war. (Temporary year-round DST, also known as "War Time," reappeared in the U.S. during World War II.)
Congress would revisit standard time in the 1960s on the recommendation of the Interstate Commerce Commission. The Uniform Time Act of 1966 established new dates for DST, and allowed individual states to exempt themselves from observing Daylight Saving Time (which is the case in several jurisdictions, including Arizona, Hawaii, and the U.S. territories).
Over the years, Congress has reviewed the issue of DST, and examined issues related to health and safety impacts, energy cost savings, and effects on productivity. The specific dates to "spring forward" and "fall back" have changed several times, most recently in 2005. Bills calling for the adoption of permanent DST have also seen bipartisan support in both the House (H.R. 1279) and the Senate (S. 582). Neither "Sunshine Protection Act" has advanced to a floor vote in the current Congress, although a previous version of the bill did pass a Senate vote in the last Congress before failing to be considered in the House.
This proposed federal change would allow states to adopt permanent daylight time (in addition to the already-existing option of permanent standard time). Currently, twenty states stand ready to adopt or consider permanent daylight time as soon as Congress takes action, according to the National Conference of State Legislatures. For now, though, we'll need to keep changing the clocks twice a year in most states. To be sure you've set up a multi-time zone meeting correctly, be sure to check the helpful government website Time.gov, giving a map of the current time in every U.S. time zone.
For more information about the legislative history of Daylight Saving Time, check out the resources in the research guide to Federal Legislative History or Ask a Librarian.